Free Calculator

Percentage Calculator

Work out percentages instantly — what % one number is of another, a percentage of a value, or the percentage change between two numbers.

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Free Percentage Calculator — Work Out Any Percentage Instantly

Need to work out a percentage fast? Parix.ai’s free percentage calculator handles the three calculations people reach for most — finding a percentage of a number, working out what percentage one number is of another, and the percentage increase or decrease between two values. Type your numbers and the answer appears instantly, right in your browser, with a plain-English breakdown of how it was worked out.

No sign-up, no app, and no waiting for a “calculate” button — just quick, accurate results every time.

Three calculators in one

Most questions about percentages fall into three buckets, and this percentage calculator online covers all of them:

What is A% of B? — Find a percentage of a number, like 20% of 250. Perfect for tips, taxes, and commissions.
A is what percent of B? — See what share one number is of another, like 25 out of 200. Great for scores, progress, and ratios.
Percentage change from A to B — Work out the percentage increase or percentage decrease between two figures, like a price moving from 80 to 100.

Just pick a mode, type your two numbers, and the result updates as you go. The labels change to match the mode, so you always know which value goes where.

Why use an online percentage calculator?

Percentages come up everywhere — and getting them wrong is easy when you’re doing the math in your head. A dedicated percentages calculator removes the guesswork and shows the steps, so you can both trust the answer and understand it.

This one is also completely private and free. It runs entirely in your browser, so nothing you type is uploaded, and there’s no limit on how many calculations you run. Whether you need a percentage increase calculator for a report or a quick percent of calculator for a shopping trip, it’s ready the moment the page loads.

What makes it handy:

Instant results — calculates as you type, with no page reload
Plain-English breakdown — every answer comes with a sentence explaining the formula
Works everywhere — desktop or mobile, no download required
Free forever — unlimited calculations, no watermark, no account

What people use it for

A good percentage calculator earns its place in everyday life:

Shopping & discounts — see how much you save, or what a price becomes after a percentage off
Business & finance — calculate margins, growth rates, commissions, and tips
School & homework — check percentage problems and learn the steps behind them
Reports & dashboards — find the percentage change between two figures in seconds

For sale prices specifically, the Discount Calculator goes a step further, showing the final price and your savings side by side.

Quick percentage formulas

If you’d rather understand the math, here are the formulas this tool uses behind the scenes:

Percentage of a number: (percent × number) ÷ 100. So 20% of 250 = (20 × 250) ÷ 100 = 50.
What percent one number is of another: (part ÷ whole) × 100. So 25 out of 200 = (25 ÷ 200) × 100 = 12.5%.
Percentage change: ((new − old) ÷ old) × 100. So 80 to 100 = (20 ÷ 80) × 100 = 25% increase.

A quick mental trick: 10% is just the number with the decimal moved one place to the left, and you can build the rest from there — 5% is half of 10%, and 20% is double.

Explore more free calculators

Working with numbers rarely stops at percentages. Crunch a loan with the EMI / Loan Calculator to see your monthly payment and total interest, or work out an exact age with the Age Calculator.

Browse the full set of free AI tools to handle more of your everyday math, money, and document tasks in one place — all free and private.

Ready to crunch the numbers? Scroll up, pick your mode, and get your percentage in an instant.

Why Use This Percentage Calculator?

Everyone learned percentage formulas at school and almost nobody remembers which one applies under pressure. This percentage calculator covers the common cases: a percentage of a number, an increase, a decrease, and the difference between two figures. Enter the numbers and read the answer. Free, instant, and no formula to look up first.

Step by step

How to use the Percentage Calculator

Pick what to calculate

Choose a mode: a percentage of a value, A as a percent of B, or the percentage change between two numbers.

Enter your two numbers

Type values into A and B. The labels update to match the mode so you always know what goes where.

Get the answer instantly

Your result appears immediately with a one-line explanation — no calculate button, no waiting.

Why you'll like it

Features & benefits

Instant results

Calculates as you type — no button press, no page reload.

Three calculations in one

Percentage of a number, A% of B, and percentage change, all in one tool.

Plain-English breakdown

Every answer comes with a sentence explaining how it was worked out.

100% private

Runs entirely in your browser — nothing you type is uploaded.

Works everywhere

Use it on desktop or mobile — no app and no sign-up needed.

Free forever

Unlimited calculations at no cost, with no limits or watermark.

What people use it for

Use cases

Shopping & discounts

See how much you save, or what a price becomes after a percentage off.

Business & finance

Calculate margins, growth rates, commissions, and tips in seconds.

School & homework

Check percentage problems and understand the steps behind them.

Reporting

Find the percentage change between two figures for reports and dashboards.

Questions answered

Frequently asked questions

Everything you might be wondering about the Percentage Calculator.

How do I calculate what percentage one number is of another?

Divide the part by the whole and multiply by 100. For example, 25 out of 200 is (25 ÷ 200) × 100 = 12.5%. Use the "A is what percent of B?" mode and the calculator does it instantly.

How do I work out a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 20% of 250 is (20 × 250) ÷ 100 = 50. Pick the "What is A% of B?" mode.

How is percentage increase or decrease calculated?

Subtract the old value from the new value, divide by the old value, and multiply by 100. A move from 80 to 100 is a 25% increase. Use the "Percentage change" mode.

Is this calculator free and private?

Yes — it runs entirely in your browser, there is no sign-up, and nothing you type is sent to a server.

How do I calculate a percentage in my head?

Quick tricks: 10% is the number with the decimal moved one place left, and 1% moves it two places. Build the rest from those — 20% is double 10%, 5% is half of 10%, and 15% is 10% plus 5%. You can also swap the numbers: 8% of 50 equals 50% of 8 = 4.

How do I add or subtract a percentage from a number?

To add, multiply by (1 + percentage/100): a 15% tip on $40 is 40 × 1.15 = $46. To subtract, multiply by (1 − percentage/100): 20% off $80 is 80 × 0.80 = $64.

What is the difference between percentage and percentage points?

A percentage is relative; a percentage point is absolute. If a rate rises from 10% to 12%, that is a 2 percentage-point increase but a 20% increase (2 ÷ 10). Confusing the two is a common reporting mistake.

How do I convert a decimal or fraction to a percentage?

Multiply by 100 and add a % sign: 0.25 becomes 25%, and 3/4 (= 0.75) becomes 75%. To go the other way, divide the percentage by 100.

How do I find the original price before a discount or tax?

Divide rather than subtract. If $90 is the price after 25% off, the original was 90 ÷ 0.75 = $120. If $114 includes 14% tax, the pre-tax price was 114 ÷ 1.14 = $100.

Can it handle percentages over 100%?

Yes. 150% of 200 is 300, and going from 40 to 100 is a 150% increase. The calculator works with any positive or negative numbers.

See it in action